December in Jasper is the most freezing month of the year. In December, the weather in Jasper is typically freezing. Average daily high temperature in December is about 10 degrees below zero. On average, Jasper has 17 cloudy, 9 snowy, 3 sunny, and 2 partly cloudy days in December. The snowfalls are usually light. December as well as January, April, May, and June is considered the most uncomfortable time to visit Jasper.